1. Field of the Invention
This invention relates to an electron beam device, a data processor for the electron beam device, and a method of producing stereo data of the electron beam device, for converting images obtained with an electron microscope into images for stereovision and for finding shapes of specimens. This invention also relates to a reference template and the preparation thereof for use in obtaining parameters necessary for correcting deviation of three-dimensional images obtained with the electron microscope and necessary for correcting lens distortion.
2. Description of the Related Art
For three-dimensional viewing of a specimen with a transmission electron microscope (TEM), the specimen is tilted to obtain right and left transmission images at different tilt angles, and right and left images are used for stereovision. In the case of the stereovision with a scanning electron microscope (SEM), either the beam of electrons or the specimen is tilted to obtain right and left images reflected at different angles, and each of the images is viewed with one eye (Refer to Medical and Biological Electron Microscopy, pp. 278-299, 1982). The above methods, like in the stereovision with unaided eyes, provide images that suffice to observe general irregularities of the specimen.
On the other hand, in the case of performing three-dimensional observation by obtaining right and left images taken from different tilt angles to perform accurate measurement of a three-dimensional shape, very accurate angular control down to the order of a few seconds is required for the tilt angle of the specimen, and for the tilt angle of the beam of electrons to reduce the, effect of aberration in the electron lens system of the electron microscope. In conventional methods, however, there is a problem that the angular control is done generally in the order of a few degrees or a few minutes and therefore the control accuracy is insufficient for, performing accurate measurement of three-dimensional shapes by the stereovision of the right and left images.